(In reply to Sylvain BERTRAND from comment #11)
> bisected: e2a9ca29b5edc89da2fddeae30e1070b272395c5
> 
> This commit is one in a series related to new TSC code

That's not consistent with the merge commit you identified earlier. So I'm
afraid it's likely that you incorrectly classified some commits as good or bad.
Maybe the problem doesn't occur 100% consistently even with bad commits, so try
testing longer / more times before declaring a commit as good.